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<h4 class="subsection" id="SH-Built_002din-Functions-1"><span>6.60.32 SH Built-in Functions<a class="copiable-link" href="#SH-Built_002din-Functions-1"> &para;</a></span></h4>
<p>The following built-in functions are supported on the SH1, SH2, SH3 and SH4
families of processors:
</p>
<dl class="first-deftypefn">
<dt class="deftypefn" id="index-_005f_005fbuiltin_005fset_005fthread_005fpointer"><span class="category-def">Built-in Function: </span><span><code class="def-type">void</code> <strong class="def-name">__builtin_set_thread_pointer</strong> <code class="def-code-arguments">(void *<var class="var">ptr</var>)</code><a class="copiable-link" href="#index-_005f_005fbuiltin_005fset_005fthread_005fpointer"> &para;</a></span></dt>
<dd><p>Sets the &lsquo;<samp class="samp">GBR</samp>&rsquo; register to the specified value <var class="var">ptr</var>.  This is usually
used by system code that manages threads and execution contexts.  The compiler
normally does not generate code that modifies the contents of &lsquo;<samp class="samp">GBR</samp>&rsquo; and
thus the value is preserved across function calls.  Changing the &lsquo;<samp class="samp">GBR</samp>&rsquo;
value in user code must be done with caution, since the compiler might use
&lsquo;<samp class="samp">GBR</samp>&rsquo; in order to access thread local variables.
</p>
</dd></dl>

<dl class="first-deftypefn">
<dt class="deftypefn" id="index-_005f_005fbuiltin_005fthread_005fpointer-1"><span class="category-def">Built-in Function: </span><span><code class="def-type">void *</code> <strong class="def-name">__builtin_thread_pointer</strong> <code class="def-code-arguments">(void)</code><a class="copiable-link" href="#index-_005f_005fbuiltin_005fthread_005fpointer-1"> &para;</a></span></dt>
<dd><p>Returns the value that is currently set in the &lsquo;<samp class="samp">GBR</samp>&rsquo; register.
Memory loads and stores that use the thread pointer as a base address are
turned into &lsquo;<samp class="samp">GBR</samp>&rsquo; based displacement loads and stores, if possible.
For example:
</p><div class="example smallexample">
<pre class="example-preformatted">struct my_tcb
{
   int a, b, c, d, e;
};

int get_tcb_value (void)
{
  // Generate &lsquo;<samp class="samp">mov.l @(8,gbr),r0</samp>&rsquo; instruction
  return ((my_tcb*)__builtin_thread_pointer ())-&gt;c;
}

</pre></div>
</dd></dl>

<dl class="first-deftypefn">
<dt class="deftypefn" id="index-_005f_005fbuiltin_005fsh_005fget_005ffpscr"><span class="category-def">Built-in Function: </span><span><code class="def-type">unsigned int</code> <strong class="def-name">__builtin_sh_get_fpscr</strong> <code class="def-code-arguments">(void)</code><a class="copiable-link" href="#index-_005f_005fbuiltin_005fsh_005fget_005ffpscr"> &para;</a></span></dt>
<dd><p>Returns the value that is currently set in the &lsquo;<samp class="samp">FPSCR</samp>&rsquo; register.
</p></dd></dl>

<dl class="first-deftypefn">
<dt class="deftypefn" id="index-_005f_005fbuiltin_005fsh_005fset_005ffpscr"><span class="category-def">Built-in Function: </span><span><code class="def-type">void</code> <strong class="def-name">__builtin_sh_set_fpscr</strong> <code class="def-code-arguments">(unsigned int <var class="var">val</var>)</code><a class="copiable-link" href="#index-_005f_005fbuiltin_005fsh_005fset_005ffpscr"> &para;</a></span></dt>
<dd><p>Sets the &lsquo;<samp class="samp">FPSCR</samp>&rsquo; register to the specified value <var class="var">val</var>, while
preserving the current values of the FR, SZ and PR bits.
</p></dd></dl>

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